JPS6097653A - Semiconductor device - Google Patents

Abstract

PURPOSE:To produce multiple pin resin sealed semiconductor device subject to easy installation with less lead bending by a method wherein the external leads bent inward along the resin main body and the other external leads bent outward and stepwise are alternately arranged. CONSTITUTION:External lead 3a bent outward and stepwise outside a resin main body 1 and the other external leads 3b bent inward along the resin main body 1 are alternately arranged at the side of the resin main body 1. The bottom points of the leads 3b and 3a are made flush to make installation of wiring pads 12, 13 for contact on a print wiring substrate 11 easier. The outside wiring pads 12 and the inside wiring pads 13 are also alternately arranged so that the pad width size may be designed wider requiring less precision of the wiring pattern as well as less precision of locating semiconductor device on the substrate 11 in case of installation.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a resin-sealed semiconductor device, and particularly to a multi-pin semiconductor device having many external lead terminals.

BACKGROUND ART Recently, as electronic devices such as watches and electronic desktop calculators have become smaller and display elements such as liquid crystals have come to be directly driven by semiconductor elements, multi-pin type semiconductors with many external lead terminals from semiconductor elements have become available. I'm starting to get used to the equipment. On the other hand, in order to improve the reliability of the encapsulating resin, semiconductor devices used in electronic devices such as those mentioned above are being encapsulated with inexpensive resin instead of using the conventional expensive ceramic case. is becoming common.

Multi-pin type semiconductor devices have traditionally included flat type semiconductor devices in which the leads protrude from the resin body in an almost horizontal direction,
There is a shrink DIP semiconductor device.

In the conventional seven-rat type semiconductor device, as shown in the perspective view of FIG. 1, external lead terminals 2 extending from four sides of a resin body 1 are bent in a step-like manner.

In such a conventional 7-rat type semiconductor device, it is possible to have up to 100 external lead terminals, but because the width of the external lead terminals is narrow, lead bending is likely to occur, and adjacent leads may come into contact with each other. However, when mounting the semiconductor device on a printed circuit board, a high degree of alignment accuracy was required between the board and the semiconductor device, which often led to problems such as difficulty in mounting. On the other hand, products with external lead terminals of about 200 pins are produced in ceramic packages, but in order to reduce costs,
The realization of about 200 pins using a resin-sealed semiconductor device is also being considered.

Purpose of the Invention The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a resin-sealed semiconductor device with 100 pins or more that is easy to mount and is easy to mount. There is.

20 Structure of the Invention In the resin-sealed semiconductor device of the present invention, the external leads protruding from the resin body are bent inward along the resin body.
The leads are arranged alternately and the lowest points of the leads are all on the same plane.

E, Example The present invention will be explained below using examples.

FIG. 2(a) is a perspective view of the first embodiment of the present invention.
FIG. 5B is a sectional view taken along line A-A of the semiconductor device shown in FIG. 1A mounted on a printed circuit board. In these figures, the external leads coming out of the four sides of the resin body 1 are the leads 3a bent in a step-like manner to the outside of the resin body 1.
and the lead 3 bent inward along the side of the resin body.
b are arranged alternately.

In such a semiconductor device of the present invention, the pitch between the external leads 3a is twice the pitch between the external leads 2 of the conventional semiconductor device shown in FIG. 1, so that short-circuits between the leads do not occur. . Furthermore, when mounted on the printed circuit board 11, the lowest points of the leads 3a bent inwardly along the resin body 1 and outwardly bent with the lead 3b are on the same plane. Figure 3 shows a conventional printed circuit board 21 for a 7-rat semiconductor device.
This is a pattern of contact wiring pads 22. The pitch between the contact wiring pads 22 must be equal to the pitch of the leads 2 of the flat semiconductor device to be mounted, as shown in FIG. 1, so as the number of external lead terminals increases, the pitch becomes smaller. Second, the pad width of the contact wiring pad 22 is narrow, and high etching accuracy is required during the manufacture of the printed circuit board. Further, since the width of the contact wiring pad 22 of the flint board 21 is narrow, very high precision is required for positioning the semiconductor device with respect to the printed circuit board during mounting.

On the other hand, FIG. 4 shows patterns 12 and 13 of contact wiring pads of the printed circuit board 11 for a semiconductor device according to the present invention. The contact wiring pad is the outer wiring pad 12.
Since the wiring pads 13 on the inner periphery are arranged alternately,
Wiring pad width dimension can be designed larger. Therefore, high accuracy of the wiring pattern is not required, and the positioning accuracy of the semiconductor device with respect to the printed circuit board during mounting can also be lower than in the past. As described above, the present invention, which has advantages in designing and mounting printed circuit boards, also has advantages in manufacturing methods for multi-pin semiconductor devices.

FIG. 5 is a diagram for explaining the second embodiment of the present invention. FIG. The leads are held by the tights (-4).According to the conventional manufacturing method for flat semiconductor devices, the leads are bent after the tights (-4) are cut out and separated with a cutting punch 31. For this reason, it is necessary to provide sufficient space between the adjacent external leads 2 to allow the cutting punch 31 to fit therein. FIG. A wide external lead 5a and a narrow external lead 5b are protruding.Since the external lead 5a is bent in a stepped manner toward the outside of the resin body 1, the lead width is designed to be wide to prevent reeds and lead deformation. have an effect.

Furthermore, since the external leads 5b are bent inward along the resin body 1, there is no possibility of lead deformation, and the lead width is narrowed in order to increase the number of pins. External lead 5a
.

The tie bar 6 holding the external lead 5b is not cut out with a cutting punch as in the conventional case, but is cut and bent using a cutting and crushing die 32 to separate the external lead 5a and the external lead 5b. According to this method, the narrower the lead spacing, the less noticeable the remaining portion of the tie bar 6 after lead molding becomes, so it is unnecessary to leave the lead spacing ten minutes apart as in conventional semiconductor devices. In addition, since the lead width of the external lead can be increased against conventional lead deformation, the semiconductor device has strong strength against impact, and lead deformation can be reduced.

21 Effects of the Invention As described above, according to the present invention, it is possible to increase the number of pins to 100 pins or more, and to facilitate mounting on a printed circuit board. Moreover, the semiconductor device of the present invention has the advantage that it can be manufactured at a much lower cost than ceramic semiconductor devices.

Although the example shows a flat semiconductor device in which the external lead terminals protrude from the resin body in four directions, it can also be applied to a mini-flat semiconductor device in which the external lead terminals protrude in two directions. The invention is not limited to semiconductor devices.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional flat semiconductor device, and Figure 2 (
(a) is a perspective view of a first embodiment of a flat semiconductor device according to the present invention; FIG. 3 (b) is a sectional view taken along line A-A of the semiconductor device shown in FIG. 4 is a plan view of a contact wiring pad pattern of a printed circuit board on which a conventional flat semiconductor device is mounted, FIG. 4 is a plan view of a contact wiring pad pattern of a printed circuit board on which a flat semiconductor device according to the present invention is mounted, and FIG. a)
5(b) is a partial plan view of a conventional flat semiconductor device in a state before cutting and bending, and FIG. 5(b) is a partial plan view of a flat semiconductor device according to a second embodiment of the present invention in a state before cutting and bending. DESCRIPTION OF SYMBOLS 1...Resin main body, 2...Conventional external lead, 3a, 5a...External lead pulled out outward, 3b. 5b... External lead bent inward, 4.6.
... Tie bar, 11.21 ... Printed circuit board, 12.13.22 ... Wiring pad for contact, 31 ... Punch for punching tie bar, 32. - Group/tie bar cutting and lead bending mold. Ward 1

Claims (1)

[Claims] What is claimed is: 1. A semiconductor device comprising a single lead and a lead bent stepwise outward from a resin body, and wherein these leads are arranged alternately.